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-rw-r--r--libmincrypt/rsa_e_f4.c259
1 files changed, 0 insertions, 259 deletions
diff --git a/libmincrypt/rsa_e_f4.c b/libmincrypt/rsa_e_f4.c
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index 17a2de2..0000000
--- a/libmincrypt/rsa_e_f4.c
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@@ -1,259 +0,0 @@
-/* rsa_e_f4.c
-**
-** Copyright 2012, The Android Open Source Project
-**
-** Redistribution and use in source and binary forms, with or without
-** modification, are permitted provided that the following conditions are met:
-** * Redistributions of source code must retain the above copyright
-** notice, this list of conditions and the following disclaimer.
-** * Redistributions in binary form must reproduce the above copyright
-** notice, this list of conditions and the following disclaimer in the
-** documentation and/or other materials provided with the distribution.
-** * Neither the name of Google Inc. nor the names of its contributors may
-** be used to endorse or promote products derived from this software
-** without specific prior written permission.
-**
-** THIS SOFTWARE IS PROVIDED BY Google Inc. ``AS IS'' AND ANY EXPRESS OR
-** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
-** MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
-** EVENT SHALL Google Inc. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
-** PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
-** OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
-** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
-** OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
-** ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-*/
-
-#include "mincrypt/rsa.h"
-#include "mincrypt/sha.h"
-#include "mincrypt/sha256.h"
-
-// a[] -= mod
-static void subM(const RSAPublicKey* key,
- uint32_t* a) {
- int64_t A = 0;
- int i;
- for (i = 0; i < key->len; ++i) {
- A += (uint64_t)a[i] - key->n[i];
- a[i] = (uint32_t)A;
- A >>= 32;
- }
-}
-
-// return a[] >= mod
-static int geM(const RSAPublicKey* key,
- const uint32_t* a) {
- int i;
- for (i = key->len; i;) {
- --i;
- if (a[i] < key->n[i]) return 0;
- if (a[i] > key->n[i]) return 1;
- }
- return 1; // equal
-}
-
-// montgomery c[] += a * b[] / R % mod
-static void montMulAdd(const RSAPublicKey* key,
- uint32_t* c,
- const uint32_t a,
- const uint32_t* b) {
- uint64_t A = (uint64_t)a * b[0] + c[0];
- uint32_t d0 = (uint32_t)A * key->n0inv;
- uint64_t B = (uint64_t)d0 * key->n[0] + (uint32_t)A;
- int i;
-
- for (i = 1; i < key->len; ++i) {
- A = (A >> 32) + (uint64_t)a * b[i] + c[i];
- B = (B >> 32) + (uint64_t)d0 * key->n[i] + (uint32_t)A;
- c[i - 1] = (uint32_t)B;
- }
-
- A = (A >> 32) + (B >> 32);
-
- c[i - 1] = (uint32_t)A;
-
- if (A >> 32) {
- subM(key, c);
- }
-}
-
-// montgomery c[] = a[] * b[] / R % mod
-static void montMul(const RSAPublicKey* key,
- uint32_t* c,
- const uint32_t* a,
- const uint32_t* b) {
- int i;
- for (i = 0; i < key->len; ++i) {
- c[i] = 0;
- }
- for (i = 0; i < key->len; ++i) {
- montMulAdd(key, c, a[i], b);
- }
-}
-
-// In-place public exponentiation.
-// Input and output big-endian byte array in inout.
-static void modpowF4(const RSAPublicKey* key,
- uint8_t* inout) {
- uint32_t a[RSANUMWORDS];
- uint32_t aR[RSANUMWORDS];
- uint32_t aaR[RSANUMWORDS];
- uint32_t* aaa = aaR; // Re-use location.
- int i;
-
- // Convert from big endian byte array to little endian word array.
- for (i = 0; i < key->len; ++i) {
- uint32_t tmp =
- (inout[((key->len - 1 - i) * 4) + 0] << 24) |
- (inout[((key->len - 1 - i) * 4) + 1] << 16) |
- (inout[((key->len - 1 - i) * 4) + 2] << 8) |
- (inout[((key->len - 1 - i) * 4) + 3] << 0);
- a[i] = tmp;
- }
-
- montMul(key, aR, a, key->rr); // aR = a * RR / R mod M
- for (i = 0; i < 16; i += 2) {
- montMul(key, aaR, aR, aR); // aaR = aR * aR / R mod M
- montMul(key, aR, aaR, aaR); // aR = aaR * aaR / R mod M
- }
- montMul(key, aaa, aR, a); // aaa = aR * a / R mod M
-
- // Make sure aaa < mod; aaa is at most 1x mod too large.
- if (geM(key, aaa)) {
- subM(key, aaa);
- }
-
- // Convert to bigendian byte array
- for (i = key->len - 1; i >= 0; --i) {
- uint32_t tmp = aaa[i];
- *inout++ = tmp >> 24;
- *inout++ = tmp >> 16;
- *inout++ = tmp >> 8;
- *inout++ = tmp >> 0;
- }
-}
-
-// Expected PKCS1.5 signature padding bytes, for a keytool RSA signature.
-// Has the 0-length optional parameter encoded in the ASN1 (as opposed to the
-// other flavor which omits the optional parameter entirely). This code does not
-// accept signatures without the optional parameter.
-/*
-static const uint8_t sha_padding[RSANUMBYTES] = {
-0x00,0x01,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0x00,0x30,0x21,0x30,0x09,0x06,0x05,0x2b,0x0e,0x03,0x02,0x1a,0x05,0x00,0x04,0x14,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
-};
-
-static const uint8_t sha256_padding[RSANUMBYTES] = {
- 0x00,0x01,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
- 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
- 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
- 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
- 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
-
- 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
- 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
- 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
- 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
- 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
-
- 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
- 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
- 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
- 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
- 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
-
- 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0x00,0x30,0x31,0x30,
- 0x0d,0x06,0x09,0x60,0x86,0x48,0x01,0x65,0x03,0x04,0x02,0x01,0x05,
- 0x00,0x04,0x20,
-
- // 32 bytes of hash go here.
- 0,0,0,0,0,0,0,0,
- 0,0,0,0,0,0,0,0,
- 0,0,0,0,0,0,0,0,
- 0,0,0,0,0,0,0,0,
-};
-
-*/
-
-// SHA-1 of PKCS1.5 signature sha_padding for 2048 bit, as above.
-// At the location of the bytes of the hash all 00 are hashed.
-static const uint8_t kExpectedPadShaRsa2048[SHA_DIGEST_SIZE] = {
- 0xdc, 0xbd, 0xbe, 0x42, 0xd5, 0xf5, 0xa7, 0x2e, 0x6e, 0xfc,
- 0xf5, 0x5d, 0xaf, 0x9d, 0xea, 0x68, 0x7c, 0xfb, 0xf1, 0x67
-};
-
-// SHA-256 of PKCS1.5 signature sha256_padding for 2048 bit, as above.
-// At the location of the bytes of the hash all 00 are hashed.
-static const uint8_t kExpectedPadSha256Rsa2048[SHA256_DIGEST_SIZE] = {
- 0xab, 0x28, 0x8d, 0x8a, 0xd7, 0xd9, 0x59, 0x92,
- 0xba, 0xcc, 0xf8, 0x67, 0x20, 0xe1, 0x15, 0x2e,
- 0x39, 0x8d, 0x80, 0x36, 0xd6, 0x6f, 0xf0, 0xfd,
- 0x90, 0xe8, 0x7d, 0x8b, 0xe1, 0x7c, 0x87, 0x59,
-};
-
-// Verify a 2048 bit RSA e=65537 PKCS1.5 signature against an expected
-// SHA-1 hash. Returns 0 on failure, 1 on success.
-int RSA_e_f4_verify(const RSAPublicKey* key,
- const uint8_t* signature,
- const int len,
- const uint8_t* hash,
- const int hash_len) {
- uint8_t buf[RSANUMBYTES];
- int i;
- const uint8_t* padding_hash;
-
- switch (hash_len) {
- case SHA_DIGEST_SIZE:
- padding_hash = kExpectedPadShaRsa2048;
- break;
- case SHA256_DIGEST_SIZE:
- padding_hash = kExpectedPadSha256Rsa2048;
- break;
- default:
- return 0; // unsupported hash
- }
-
- if (key->len != RSANUMWORDS) {
- return 0; // Wrong key passed in.
- }
-
- if (len != sizeof(buf)) {
- return 0; // Wrong input length.
- }
-
- if (key->exponent != 65537) {
- return 0; // Wrong exponent.
- }
-
- for (i = 0; i < len; ++i) { // Copy input to local workspace.
- buf[i] = signature[i];
- }
-
- modpowF4(key, buf); // In-place exponentiation.
-
- // Xor sha portion, so it all becomes 00 iff equal.
- for (i = len - hash_len; i < len; ++i) {
- buf[i] ^= *hash++;
- }
-
- // Hash resulting buf, in-place.
- switch (hash_len) {
- case SHA_DIGEST_SIZE:
- SHA_hash(buf, len, buf);
- break;
- case SHA256_DIGEST_SIZE:
- SHA256_hash(buf, len, buf);
- break;
- default:
- return 0;
- }
-
- // Compare against expected hash value.
- for (i = 0; i < hash_len; ++i) {
- if (buf[i] != padding_hash[i]) {
- return 0;
- }
- }
-
- return 1; // All checked out OK.
-}
generated by cgit v1.1 at 2024-09-28 22:48:29 +0000